How do iframe busters for expandable ads work?
I have some questions about expandable ads and <iframe>s. I've created expandable ads which will displayed in <iframe>s. These ads will be served by known adservers like doubleclick, smartadserver, eyewonder, etc.
Thanks to some questions on Stack Overflow, I've discovered that they are some ways to break the ads out of the <iframe>s or even to dynamically resize the <iframe>s.
I've found <iframe> buster files from the main ad serving company on the Internet, but I don't really get how they work.
I know that I have to create a HTML file which I'll be giving along with my ad tag to the publisher, and they'll need to put it under their domain. But I don't understand how that file works. How do I interact with it from my JS?
Answer
The HTML file allows the ad vendor to load their own javascript on the domain of the hosting HTML file. Normally, its a 3 step process.
- Ad loads within an iframe on an ad server domain (ads.adserver.com) versus the site domain (www.example.com).
- Ad detects its in such an iframe and loads in yet another iframe to an HTML file on www.example.com, passing in parameters to the HTML file
- HTML file then in turns loads in the ad (first finding the iframe the ad was loading in to determine location) and places it on the parent website DOM structure, which it has access to thanks to the fact that it is the same domain.